The Box.net implementation has begun in this version. box.net are using OAuth2.0 as their authentication process. I have successfully setup the authentication process up to the retreival and storage of the access token, i.e. CloudTree is authenticated with Box.net, but retention of the access token is yet to be coded. 

Box.net uses cURL POST to respond with access tokens. Converting this process over to .NET POST methods is yet to be completed.

I will be directing my efforts towards completing the dropbox user interface for the following 2 days, an update will follow.
I have completed a full Dropbox access token procedure using the OAuth1.0 implementation - this procedure has been designed to commit this access token to the database, relitive to the logged in user.